|
| 1 | +from dataclasses import dataclass |
| 2 | +from typing import List, Tuple |
| 3 | + |
| 4 | +import openvino as ov |
| 5 | +import torch |
| 6 | + |
| 7 | +from vllm.attention.backends.abstract import (AttentionBackend, |
| 8 | + AttentionMetadata) |
| 9 | + |
| 10 | + |
| 11 | +class OpenVINOAttentionBackend(AttentionBackend): |
| 12 | + |
| 13 | + @staticmethod |
| 14 | + def get_name() -> str: |
| 15 | + return "openvino" |
| 16 | + |
| 17 | + @staticmethod |
| 18 | + def get_impl_cls(): |
| 19 | + # OpenVINO implements PagedAttention as part of the Optimum |
| 20 | + # exported model |
| 21 | + raise NotImplementedError |
| 22 | + |
| 23 | + @staticmethod |
| 24 | + def make_metadata(*args, **kwargs) -> "AttentionMetadata": |
| 25 | + raise NotImplementedError |
| 26 | + |
| 27 | + @staticmethod |
| 28 | + def make_openvino_metadata(*args, **kwargs) -> "OpenVINOAttentionMetadata": |
| 29 | + return OpenVINOAttentionMetadata(*args, **kwargs) |
| 30 | + |
| 31 | + @staticmethod |
| 32 | + def get_kv_cache_shape( |
| 33 | + num_blocks: int, |
| 34 | + block_size: int, |
| 35 | + num_kv_heads: int, |
| 36 | + head_size: int, |
| 37 | + ) -> Tuple[int, ...]: |
| 38 | + return (2, num_blocks, num_kv_heads, block_size, head_size) |
| 39 | + |
| 40 | + @staticmethod |
| 41 | + def swap_blocks( |
| 42 | + src_kv_cache: ov.Tensor, |
| 43 | + dst_kv_cache: ov.Tensor, |
| 44 | + src_to_dst: torch.Tensor, |
| 45 | + ) -> None: |
| 46 | + # OpenVINO currently supports only CPU, which does not require |
| 47 | + # swap of KV cache blocks |
| 48 | + raise NotImplementedError |
| 49 | + |
| 50 | + @staticmethod |
| 51 | + def copy_blocks( |
| 52 | + kv_caches: List[Tuple[ov.Tensor, ov.Tensor]], |
| 53 | + src_to_dists: List[Tuple[int, int]], |
| 54 | + ) -> None: |
| 55 | + for src, dst in src_to_dists: |
| 56 | + for key_cache, value_cache in kv_caches: |
| 57 | + key_cache.data[dst, :] = key_cache.data[src, :] |
| 58 | + value_cache.data[dst, :] = value_cache.data[src, :] |
| 59 | + |
| 60 | + |
| 61 | +@dataclass |
| 62 | +class OpenVINOAttentionMetadata: |
| 63 | + """Metadata for OpenVINOAttentionBackend. |
| 64 | +
|
| 65 | + Basic terms used below: |
| 66 | + - batch_size_in_sequences - total number of sequences to execute |
| 67 | + - prompt_lens – per sequence size number of scheduled tokens |
| 68 | + - batch_size_in_tokens = sum(prompt_lens) |
| 69 | + - max_context_len = max(context_lens) |
| 70 | + - max_num_blocks = div_up(max_context_len / BLOCK_SIZE) |
| 71 | + - num_blocks – total number of blocks in block_indices |
| 72 | + """ |
| 73 | + |
| 74 | + # Describes past KV cache size for each sequence within a batch |
| 75 | + # Shape: [batch_size_in_sequences] |
| 76 | + # Type: i32 |
| 77 | + past_lens: torch.Tensor |
| 78 | + |
| 79 | + # Describes start indices of input / speculative tokens from |
| 80 | + # current sequences within a batch sequence |
| 81 | + # Shape: [batch_size_in_sequences + 1] |
| 82 | + # Type: i32 |
| 83 | + subsequence_begins: torch.Tensor |
| 84 | + |
| 85 | + # Describes block tables for each sequence within a batch - |
| 86 | + # indices along 0th dimension in key_cache and value_cache inputs |
| 87 | + # Shape: [num_blocks] |
| 88 | + # Type: i32 |
| 89 | + block_indices: torch.Tensor |
| 90 | + |
| 91 | + # Describes block tables for each sequence within a batch - |
| 92 | + # for i-th element, it is an index in block_indices with the |
| 93 | + # first block belonging to i-th sequence |
| 94 | + # Shape: [batch_size_in_sequences + 1] |
| 95 | + # Type: i32 |
| 96 | + block_indices_begins: torch.Tensor |
| 97 | + |
| 98 | + # Describes max context length |
| 99 | + # Shape: scalar |
| 100 | + # Type: i32 |
| 101 | + max_context_len: torch.Tensor |
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